This invention relates to a bipolar electrosurgical instrument, for use in the cutting and coagulating of tissue.
Two well-known classes of electrosurgical instrument are forceps-type devices, and electrosurgical cutting blades. A forceps-type device generally comprises a pair of jaws which can be opened and closed in order to grasp tissue between the jaws. An electrosurgical coagulating voltage is supplied between the jaws in order to cause the coagulation of the tissue held between the jaws. U.S. Pat. No. 5,258,006 is one example of such a device. If the cutting of tissue is desired in addition to vessel sealing, a mechanical cutting blade can be added to the forceps device, as in U.S. Pat. No. 5,445,638. More recently, an electrosurgical cutting blade can be provided as opposed to a mechanical blade, as in U.S. Pat. Nos. 6,174,309 and 6,554,829.
The other type of device is the electrosurgical cutting blade, which generally comprises two or more electrodes in close proximity to one another, as in U.S. Pat. Nos. 4,674,498, 4,850,353, 4,862,890 and 4,958,539. The present invention attempts to provide a surgical instrument combining the advantages of an electrosurgical cutting blade and a forceps-type device.